Cold-sawing machine



(No Model.) 3 Sheets-Sheet 1. G EHRHARDT GOLD SAWING MAGHINB.

Patented June 27, 1893.

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G. EHRHARDT.

GOLD SAWING MACHINE. No.I 500,193. Patented June 27, 1893.

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(No Model.) 3 sheets-sheet a. 4 G. EHRHARDT.

GOLD SAWING MACHINE. No. 500,193. Patented June 27k, 1893.

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GUSTAVE EHRHARDT, OF PITTSBURG, PENNSYLVANIA.

COLD-SAWING MACHINE.

SPECIFICATION forming part of Letters Patent No. 500,193, dated J une27, 1893.

Application filed July 16, 1891. Serial No. 399,762. (No model.)

To MZ whom it may concern.,-

Be it known that l, GUsTAvE EHRHARDT, a citizen of the United States,residing at Pittsburg, in the county of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements in Oold-Sawing Machines; and I do hereby declare that the following is a full,clear, and exact description of theinvention,which will enable othersskilled in the art to which it appertains to make and use the same,reference being had to the accompanying drawings, which form a part ofthis specification.

My invention relates to improvements in cold-sawing machines, and refersparticularly to the means for guiding the saw and regulating the speedof the cut; and furthermore, to the means for elevating the saw andlocking it in its elevated position.

My invention is fully described in connection with the drawings,wherein- Figure 1 is a side View of a machine embodying my improvements.Fig. 2 is a front view of the same. Fig. 3 is a plan view thereof. Fig.4 is a detail sectional view.

A represents the bed-plate provided with an ordinary slide-rest, B, anda vertical standard, C, upon which is fulcrumed a lever, D, whichcarries the saw,E. The shaft, F, upon which the lever is pivoted,carries a fly-wheel, G, and a band-wheel, H, and in addition, thereto,the said shaft carries a miter-gear, I, which meshes with a similarmiter-gear, K, which is carried by the worm-shaft, L, said worin-shaftbeing disposed longitudinally in the lever in a position to engage thepinion, M, on the shaft N, of the saw. The saw-carrying lever islongitudinally slotted to embrace a segmental guide-finger, O, which isbolted at its lower end to the front of the standard, C, the slot, d, inthe lever being of such a size that its sides bear against oppositeSides of the guide-finger, whereby lateral vibration of the lever isprevented. A rackbar, P, is bolted to the convex surface of theguide-finger, and a sliding block, Q, which is secured to the upper sideof the lever is provided in its concave surface, with a channel, q, toreceive the rack-bar.

R represents a clutch, the shaft, r, of which is mounted in bearings inthe sliding block and abracket, r', which is secured to the side of thelever. The shaft of the clutch carries a pinion, S, to engage therack-bar, and a similar pinion, s, which is adapted to be engaged by anintermeshing pinion, s', carried by the sliding shell, 3". The slidingshell is feathered on the shaft, r, and is adapted to be movedlongitudinally thereon, to engage or release the pinion, s. The outerend of the shaft is squared for the reception of an operating crank,whereby the shaft may be turned to elevate the front or saw supportingend of the lever.

T, represents a brake, which consists of a spring-arm, t, secured at oneend to the sliding-block and engaged at its free end by an adjustingscrew, U, which carries the brakeshoe, U', the brake-shoe being notchedto embrace the rack-bar. The adjusting screw7 is provided with ahand-wheel, u. The rear end of the lever, D, carries a counter-balancingweight, V, which is adapted to be adjusted to regulate the speed ofdepression of the saw. From the above description it will be seen thatthe saw is guided, during operation, to prevent lateral vibration andinsure a clear cut.

In machines of this kind, having no means for regulating the speed ofthe cut, difficulty is experienced in preventing the saw from cuttingmore rapidly, and hence less satisfactorily, in passing through a thinportion of the article which is being sawed. For instance, in sawingrailway rails, with machines now used, the saw passes more easily andquickly through the web of the rail, ow-

ing to the fact of there being less resistance v at this point, andhence, the cut is liable to be less smooth and regular, and the saw isliable to twist and pass out of a direct line. To overcome thisdifficulty is the main object of my invention, and it .is accomplishedby the construction hereinbefore described.

The counter-balancing weight is adjusted to allow the desired rate ofspeed through the main body of the article which is being operated upon,and when a thinner portion of the article, or a portion thereof whichoffers less resistance, is reached, the brake is operated to allow thesame speed as before. When a thicker portion is again reached the brakeis released. Thus, I have a self-feeding machine, in which the saw iscarried by IOO a balanced arm or lever, the speed at which the sawadvances being controlled by the excess of weight atthat end of the armor lever which carries the saw, and the said excess being regulated bythe position of the coun terbalancing weight, a quick change in thespeed of feeding being attained by the manipulation of the brake,whereby the forward movement of the saw may be instantly checked.-

To elevate the saw, the shaft of the clutch is rotated by means of thecrank, the movable shell being previously repressed to cause the pinioncarried thereby, to engage the pinion, s, and when it is desired tooperate the saw the crank is removed and the pinion, s, is released bydisengaging the pinion on the shell therefrom.

The saw may be locked in its elevated position by means of the brake.

Having thus described my invention, I claiml. The combination with a sawcarrying arm or lever, fulcrumed at an intermediate point, of anadjustable counterbalancing weight at its rear end connected to the armor lever so as to counterbalance, in a greater or less degree, theweight of the saw to regulate the speed of depression of the latter andmeans for vertically setting and braking the saw, substantially asspecified.

2. The combination with a balanced sawcarrying lever provided with alongitudinal guide-slot, of a segmental or curved guideiinger, adaptedto engage the said guide-slot, a rack-bar carried by said guide-finger,and saw-setting devices carried by the saw frame and adapted toco-operate with the said rackbar, substantially as specified.

3. The combination with a saw-carrying lever provided with aguide-slot,of a stationary segmental guide-nger engaged by said slot andhaving one of its faces concentric with the fulcrum of the lever andprovided with a rack, and a pinion carried by said lever to engage therack, substantially as specified.

4. The combination with a saw-carrying lever, provided with a guide slotand a counter-balancing weight, and a guide-nger, embraced bytheguide-slot in the lever, and provided with a rack, of a clutch, mountedupon the lever and havingr a pinion, S, to engage the rack, a pinion, s,and a loose shell carrying a pinion, s', to engage the pinion, s,substantially as specified.

5. The combination with a saw-carrying leverprovided with acounterbalancingweight and having a guide-slot, and a stationaryguide-finger concentric with the fulcrum of said lever and engaged bythe guide-slot in the latter, of a brake mounted upon the lever tompinge against the surface of the guide finger, whereby the descent ofthe saw may be regulated and checked at will, substantially asspecified.

6. The combination of a saw-carrying lever having a guide-slot, and theguide-finger provided with a rack-bar and embraced by a guide-slot inthe lever, of a clutch, carried by the lever to engage the rack-bar, anda brake mounted upon the lever and provided with an adjustablebrake-shoe to engage the guide-inger, substantially as specified.

In testimony whereof I afx my signature in the presence of twowitnesses.

GUSTAVE EHRHARDT.

Witnesses:

F. P. HAWLEY, JOHN GRAEBING, Jr.

